Sen. Charles E. Grassley of Iowa and Rep. Lamar Smith of Texas are raising more questions about the Obama administration’s new policy allowing some young undocumented immigrants to stay in the country.

In a letter Tuesday, the two Republicans asked Homeland Security Secretary Janet Napolitano to answer 10 detailed questions about the process, under which administration officials vet applications for a reprieve from deportation under the new policy announced June 15.

Grassley and Smith, the ranking member and chairman of the Judiciary committees in their respective chambers, have been outspoken in opposing the directive, saying it could be susceptible to fraud. Their letter follows an earlier request for information, sent by Smith in July, for which his committee said he never received a response.

Administration officials started accepting applications for the program in August. Under the new policy, illegal immigrants who are not older than 30 and who have lived in the United States for at least five continuous years since they were 16 can apply for “deferred action” from deportation if they can prove they are either in school or have a high school diploma. The deferrals last for two years and would allow people to get work permits.

According to documents obtained by the House Judiciary Committee, the administration has received almost 87,000 applications and approved 36. None so far have been denied.

“Because this is a discretionary decision not to pursue enforcement against a person for a specified period of time, we would ask the department to be transparent and forthcoming about the details, criteria and process of the deferred action directive,” the pair of lawmakers wrote. “It is still unclear to us what level of documentation will be required and what level of background checks are being conducted on the documents and the applicants.”

The letter asks specifically about the background checks that are to be performed on applicants and whether immigration officials plan to run the names of applicants through databases maintained by intelligence agencies. It also asks whether the administration plans to hire more staff to perform the background checks.